One known technique, for example, pertaining to the present invention is disclosed in Patent Document 1. The patent document discloses a hydraulic excavator including an upper swing structure that houses therein an engine, a cooling fan connected with the engine, and a radiator disposed anterior to the cooling fan. The hydraulic excavator further includes a reservoir tank for the radiator and the reservoir tank is disposed immediately above a shroud of the cooling fan. Additionally, the reservoir tank has a water filler port disposed at a level substantially identical to a water filler port of the radiator and the two water filler ports are connected with each other by a hose.